Question

A train of length $120m$ travels at a speed of $57km/h$. In what time it will pas a man who is walking at $3km/h$ in the opposite direction?

Answer 1

Speed of train $=57km/hr$
Speed of mass $=3km/hr$
Opposite direction $\Rightarrow$ Relative speed $=(57+3)=60km/hr$
Length $=120m=0.120km$
time $=\frac{0.120}{60}\Rightarrow 2\times {10}^{-3}$
$=0.002hr$
$=0.002\times 60\times 60$
$=7.2$ seconds